Abstract: A compressed video and audio transport stream multiplexer pre-builds a multiplex pattern in microprocessor local memory using a microprocessor with a DMA controller. The transport stream headers, a null packet, program specific information tables and packetized elementary stream buffers accessed by an assembly buffer that has DMA control blocks, two blocks per transport stream packet. The DMA control blocks are built and loaded into the assembly buffer based upon the number of packets required for the packetized elementary streams and program specific information according to the multiplex pattern. Packetized elementary stream data is received from respective sources and loaded into the packetized elementary stream buffers, and then output according to the DMA control blocks in the assembly buffer to form the transport stream.

Abstract: A network switch configured for switching data packets across multiple ports uses an address table to generate frame forwarding information. The address table represents a plurality of bins of address entries. A decision-making engine receives a source address of a frame and a receive port number and searches a particular bin in the address table for a match. When the decision-making engine does not find a match, the switch adds an entry to a particular bin in the address table. A host device may also add entries in a particular bin. In addition, entries may also be deleted from a particular bin.

Abstract: A multiple access and data channel scheme is presented for reducing network communication collisions and susceptibility to jamming signals in a distributed network to increase network connectivity and communication throughput. An order wire channel (202) is used to gain access to a data channel (204). To gain access to the data channel (204), a source radio sends a transmit probe (TXP) over the order wire channel (202) to the target radio. The target radio senses its environment and responds with a receive probe (RXP) which comprises data channel transmission parameters including the data channel frequency, transmit power, spread code, and transit timing to be used for the data transmission. Source radio moves to the data channel using the data channel transmission parameters specified by the receive probe (RXP) to communicate with the target radio. If a collision occurs of the order wire channel (202), the source radio retransmits the transmit probe after a random time period.

Abstract: Improved ISDN interface apparatus and methods permit dual mode access to an on-board memory. A first memory controller is provided that responds to addresses in a first address range to read, write or otherwise access data in an “on-board” memory a first memory access mode. A second memory controller is provided that responds to addresses in a second address range to access data in that memory in a second memory access mode. Multiplexing circuitry selectively applies control signals from the first or second memory controllers to the memory, thereby, causing it to read, write or otherwise access data according to the first or second modes. The aforementioned first and second modes can constitute differing memory access modes. Thus, for example, first mode is a single-beat memory access mode, according to one practice of the invention. The second mode can comprise, on the other hand, for example, a burst mode.

Abstract: A functional entity in a digital switch is triplicated in planes operating in parallel. From each plane, a respective passing data flow is spread to parallel planes. A majority vote function receives the data flows of the planes and compares these on a bit level for creating a majority voted data flow. A plane condition sensing function indicates whether links of the planes have meaningful information and synchronism, and emits, as a result, a link condition indicating signal for each plane. A priority select function is connected for receiving the majority voted data flow and the link condition indicating signals. If the link condition indicating signals indicate a fault condition, the priority select function lets the majority voted data flow through as an outgoing data flow from the functional entity.

Abstract: An encoder/decoder scheme for robust transmission of PHY layer frame control information (to support medium access) in OFDM frames (or packets). The PHY layer frame control information to be modulated onto carriers in OFDM symbols is encoded using a product coding to form a product code block or matrix. The product coding is based on a shortened hamming code codeword set having properties of symmetry. Elements of the product code matrix are interleaved so that the elements are modulated onto the carriers of the symbols in diagonal groupings (across time and frequency) and with some degree of redundancy. The modulated elements are demodulated to produce soft decision values, which are de-interleaved to combine copies of the soft values for elements and re-order the soft values in the order of the elements prior to interleaving.

Abstract: The present invention pertains to a system for sending ATM cells. The system comprises an ATM network along which ATM cells travel. The system comprises source nodes connected to the ATM network which produce packets having cells and transmit the cells on the ATM network. The system comprises I input switches connected to the ATM network, where I is greater than or equal to 1 and is an integer, which receive cells from the ATM network transmitted by the source node. The system comprises M intermediate switches connected to the ATM network, where M is greater than or equal to 1, which receive signals from the ATM network transmitted by at least one input switch. The intermediate switch discards cells only of a same packet when a predetermined event occurs so the discarded cells are not transmitted by the intermediate switch. The system comprises destination nodes connected to the ATM network which receive non-discarded ATM cells from the intermediate switch.

Abstract: A SS7 signalling router receives SS7 signalling regarding narrowband calls to be routed over the ATM network. When the SS7 router receives signalling from the SS7 network, it does not process the signalling, but reads the originator point code (OPC) and forwards the signalling via the ATM network to the ATM switch which is attached to the originator of the message. An interworking function (IWF) at the ATM switch processes the SS7 signalling by generating the appropriate ATM signalling to set up a circuit between the originating ATM switch and the destination ATM switch. The IWF at the originating ATM switch also processes the SS7 signalling by returning it to the SS7 router with the destination point code (DPC) of the PSTN switch coupled to the destination ATM switch. When the SS7 router receives an SS7 signalling message from an ATM switch, it forwards it to the SS7 network where it is sent to the DPC.

Abstract: An interleaving/de-interleaving scheme for providing redundancy with both time and frequency diversity to data in OFDM symbols in a data transmission system. On the transmit side, encoded data to be modulated onto carriers in OFDM symbols is interleaved by storing the encoded data in an interleaver memory and reading multiple copies of the encoded data from the interleaver memory so that the encoded data copies are spread in time on non-consecutive symbols and in frequency on non-adjacent carriers. On the receive side, the multiple copies of the OFDM data are received, and phase noise computations are used to combine the multiple copies (in either metric or phase angle form) into one. From the combined copies a single metric value to be used in decoding the OFDM data is produced.

Abstract: A method and apparatus for reducing jitter and wander on the internetworking between ATM network and PDH network is disclosed.

Abstract: A network switch configured for switching data packets across multiple ports uses an address table to generate frame forwarding information. The address table includes a virtual local area network index field. A decision-making engine receives a VLAN ID from a frame and converts the VLAN ID to a VLAN index and searches the address table for data forwarding information based on the generated VLAN index. The switch may be modified to support any number of VLANs by varying the size of the VLAN index field in the address table with minimal changes to the architecture of the switch.

Abstract: An apparatus and method for enabling the combination of multiple streams of data cells into a single thread. By enabling plural input ports of an intermediate device to access a single parallel output port of the device, plural network switch elements share a single thread through a switch fabric. For instance, the method and apparatus permit interleaving the relatively low bandwidth cell outputs of two ATM network switch central control processors onto a single thread routed through an interconnected switch fabric. Certain of these cells are received from the switch fabric at a parallel input of the intermediate device, then routed to one of plural serial output ports. Pacing of cells provided to the plural serial input ports prevents exceeding the shared thread bandwidth.

Abstract: A SPREAD ALOHA Multiple Access (SAMA) channel uses distinct chip phases to label portions of a common SAMA channel and to reserve specific phases by means of a random access packet in the same SAMA channel. In the new SAMA reservation channel protocol, reservations consisting of the specification of a given chip phase are transmitted in a random access mode in a common SAMA channel. After a given user has reserved a given chip phase, that chip phase can be used on a reserved basis by that user to guarantee a certain quality of service. The reservation can be made by a user who simply initiates transmissions with a given chip phase and continues to use that chip phase if the user's first packet (the packet making the reservation) is received correctly. The SAMA hub broadcasts a list of reserved chip phases or broadcasts a list of free chip phases to ensure that other transmitters do not use the reserved chip phase. Alternately, the hub requires a transmitter to adjust chip phases of its transmitters.

Abstract: A network routing switch includes a crosspoint switch, a set of Ethernet I/O ports, a set of ATM I/O ports, a reassembly unit for converting ATM transmissions into Ethernet transmissions, and a segmentation unit for converting Ethernet transmissions into ATM transmissions. As an ATM I/O port receives cells of an ATM transmission from an external source it stores them until the transmission is complete and then sends the ATM transmission through the crosspoint switch either to a forwarding ATM port or to the reassembly unit depending on whether the ATM transmission is to be forwarded as an ATM or Ethernet transmission. When the reassembly unit receives an ATM transmission it converts it to an Ethernet transmission and forwards it through the crosspoint switch to a forwarding Ethernet I/O port.

Abstract: A multiport data network switch includes a programmable Management Information Base (MIB) configuration register that serves as a reference for the Media Access Controller (MAC) at each port. The register is programmable for maximum packet length in two configurations. In a first configuration, the maximum packet length setting is constant for all ports. In the second configuration, the maximum packet length is set at a plurality of levels in accordance with certain dynamic conditions. On an untagged port, or on a tagged port capable of communicating with a Virtual Local Area Network (VLAN) that receives/transmits an untagged frame, the maximum packet length criterion is a first value. On a tagged port that receives/transmits a VLAN tagged frame, the maximum packet length criterion first level is expanded by the number of bytes required for the VLAN tag.

Abstract: An ATM routing switch has a plurality of output ports for handling digital signal cells on a first type requiring integrity of cell transmission and a second type accepting some loss of cells in transmission, the output ports having control circuitry to provide a plurality of queues of cells at each output port, each queue comprising only cells of a single type while each port outputs a mixture of cells of both types on a common output path flow control indicators on incoming cells being used to inhibit output of cells along any path to a destination for which a flow control indicator has indicated congestion.

Abstract: A meter-rate billing system is disclosed in which billing is performed according to an interval while a subscriber uses a network actually, without any exclusive device. The meter-rate billing system on a LAN system for controlling connections to other networks includes a table in which a subscriber information is registered, a LAN controller for retrieving the table according to said subscriber information when a subscriber accesses joining to said LAN system accesses the LAN system, registering the subscriber information in said table if the information has not been registered, updating the registration information if the subscriber information is registered, and deleting the registration information if the registration information is not updated within a predetermined interval, and a billing device for receiving the registration information stored in the table in every predetermined informing interval and judging an interval time during which the registration information is registered in the table.

Abstract: Layered Video Multicast with Retransmissions (LVMR) is a system for distributing video content using layered coding over the Internet. The two key contributions of the system are (1) improving the quality of reception within each layer by retransmitting lost packets given an upper bound on recovery time and applying an adaptive playback point scheme to help achieve more successful retransmission, and (2) adapting to network congestion and heterogeneity using a hierarchical rate control mechanism. A hierarchical rate control system and method is disclosed for regulating the flow of video information in a network by establishing subnet agents for each subnet, and by establishing intermediate agents for each domain. The subnet agents gather information concerning add-layer experiments conducted by receivers in a subnet, and the information is provided to intermediate agents of the domains for regulating data traffic.

Abstract: An arrangement and a method control the flow of signals including a number of information packets in a communications network, e.g. an ATM-network. The arrangement includes a device for separating the signals in the first traffic signals and second traffic signals. The first traffic signals are signals that have a higher proportion of guaranteed resources, i.e. bandwidth, than the second traffic signals. The first traffic signals are also given a lower priority than the second traffic signals. The first and second traffic signals are handled separately.

Abstract: A network switch routes data transmissions between network stations, each data transmission including network addresses of the source and destination network stations. The network switch includes a set of input/output (I/O) ports each for receiving data transmissions from and transmitting data transmissions to a subset of the network stations. Each I/O port is identified by a “physical” port ID and a “logical” port ID. While each I/O port's physical port ID is unique, all I/O ports that can route data to the same subset of network stations share the same logical port ID. Each I/O port receiving a data transmission from a network station sends its logical port ID and the network addresses included in the data transmission to an address translation system.